Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers

LPF Donation via Stripe | LPF Donation - Other Methods

Links below open in new window

ArcticMyst Security by Avery

MXDL Over 300mW! (LPM Reading Video pg. 2)

Gazoo

Gazoo

0
Joined
Jun 9, 2007
Messages
3,206
Points
38
Jay,
One of your components is possessed.. ;D I tried to duplicate what you are seeing using a peltier as a load and was not able to. The only difference is I used a can type 10uf 16 volt capacitor.

There was absolutely no difference in voltage going to the peltier with the cap/diode connected to it. The voltage rose to 1.5 volts then slowly began to drop as the peltier heated up. Of course the current stayed the same. This is normal since I do not have that peltier properly heatsinked yet.

I am at a total loss here. . .

In the above picture are you measuring voltage or current with your meter...it looks like it is set up to measure current.
 





jayrob

jayrob

0
Joined
Sep 21, 2007
Messages
9,862
Points
113
Hi Gazoo, I wasn't even thinking about voltage on the test circuit because the peltier is designed for 12 volts right? Using the peltier as a load, I think that I have successfully tested that the current reading I got on my MXDL is probably correct. I'm afraid I'll have to connect another open can diode to the test circuit to double check the voltage phenomenon...
Jay
 
Gazoo

Gazoo

0
Joined
Jun 9, 2007
Messages
3,206
Points
38
You did say you were getting 4 volts across the peltier with the 7135...correct? And I am saying the most I got was 1.5 volts.
 
jayrob

jayrob

0
Joined
Sep 21, 2007
Messages
9,862
Points
113
Gazoo said:
You did say you were getting 4 volts across the peltier with the 7135...correct? And I am saying the most I got was 1.5 volts.
Click to expand...

Ok...now, I am about to type another dumb question, so go easy on me...In the picture, I measured both voltage and current. Sounds like I need to connect the DMM leads so that one goes to the positive and one to the negative for voltage readings?

I also want to clarify that when I measured voltage and current readings on my MXDL 'at the LD', I just put one probe on each wire to the LD...

So, if you are about to type back what I think you are, then my voltage reading on the MXDL was correct, but I need to re-measure the current...
Jay
 
Gazoo

Gazoo

0
Joined
Jun 9, 2007
Messages
3,206
Points
38
Yes for measuring voltage you are correct. The meter probes go in parallel with the circuit, battery, device or whatever being measured.

For measuring current your meter needs to go in series with the load. Just like you did in the above picture.

If you measure the current between the power supply and the regulator, the milliamp reading should be exactly the same as if you are measuring between the output of the regulator and the load. This is true with any linear regulator..like the 317 for example.

Make sure you have your probes in the right place on the meter before you measure voltage or current.. ;)
 
jayrob

jayrob

0
Joined
Sep 21, 2007
Messages
9,862
Points
113
Gazoo said:
Yes for measuring voltage you are correct. The meter probes go in parallel with the circuit, battery, device or whatever being measured.

For measuring current your meter needs to go in series with the load. Just like you did in the above picture.

If you measure the current between the power supply and the regulator, the milliamp reading should be exactly the same as if you are measuring between the output of the regulator and the load. This is true with any linear regulator..like the 317 for example.

Make sure you have your probes in the right place on the meter before you measure voltage or current.. ;)
Click to expand...

Tell you what I'm going to do then, I will cut the positive lead to my LD on the 'freak' MXDL and connect my DMM like the picture of the peltier and measure the current.

In my defense though, right from the start of this cool hobby, I have been testing the current of the DDL drivers in the same way that I tested the MXDL. That is, one probe to each lead. And the result of the current readings were always right where they were supposed to be. Example: 5 ohms/250mA, 3.9 ohms/323mA, 4.3 ohms/294mA. So, I thought I was measuring correctly...
Jay

P.S. For sure the measurment of the LPM and the 300mW plus is correct. So, I will re-measure the current to see for sure what the 7135 is feeding the LD.
 
Gazoo

Gazoo

0
Joined
Jun 9, 2007
Messages
3,206
Points
38
You are lucky you did not damage your meter....your meter was acting like a load...this is a huge no no. Some others are finding this out too.
 
amkdeath

amkdeath

0
Joined
Oct 28, 2007
Messages
2,631
Points
48
man i so want an open can right now...

and DUDE, as much as I want to know how u did this so I can too, DONT SCREW IT UP!! you might never get something like this ever again!

I wish there was an online supplier or a GB for open cans, the cheapest I can find for a salvaged and moduled open cavity is like 35 bucks...
it would SUCK to kill a 36 dollar diode...

regards,

amk

PS. Even thought it may seem like it, I gather you are getting these results from incrased voltage input...
 
jayrob

jayrob

0
Joined
Sep 21, 2007
Messages
9,862
Points
113
Hey that power chart seems like a good bit of information to have! Thanks for posting it.

Well, I am just as confused after some more testing. I un-soldered the positive lead going to the LD and connected my DMM to test the current. I got a normal type of reading....331mA putting out 195mW.
MXDL open can - 4.jpg


This is strange to me, because when I put it back, I got readings of 317mW plus!

So, I made sure I put a fresh battery in. And once again, un-soldered the positive lead to the LD a second time, and connected the DMM....only to find the same normal type readings??

Then, I connected it back together again and here is a picture of the LPM readings...
MXDL open can - 3.jpg


Maybe the DMM is putting just a little extra load on the circuit?? I don't know, but I do know that I like the 300 + mW!
I guess I'm going to leave it like this... If anybody else comes up with any ideas, please share!

Jay
 
jayrob

jayrob

0
Joined
Sep 21, 2007
Messages
9,862
Points
113
the cheapest I can find for a salvaged and moduled open cavity is like 35 bucks...
Click to expand...

amk, that is a good price. I had to pay $29.95 plus shipping for a total of around $34 bucks just to get the DVD. Sounds like the source you mentioned isn't making anything for his efforts. And these diodes are very delicate to handle... If you want one bad enough, I would suggest buying a Pioneer 112D and carefully doing the harvest. It's not that bad. But for a guy to do it for others, man that's taking the chance he might ruin one, when it wasn't even for his own use. What DDL is doing with the Blue Rays is a great effort on his part...
Jay
 
Gazoo

Gazoo

0
Joined
Jun 9, 2007
Messages
3,206
Points
38
I think I may have figured it out...we always overlook the obvious. You say it only puts out that much milliwatts when the head is attached to the body. The reason for this is because your diode/ flashlight head is not isolated from the body, so the regulator isn't doing anything! You are running the diode straight off the battery. I suspected something like this all along because that is just exactly how your diode has been behaving. Sorry it took me this long to figure it out.

@AMK....The reason I have been trying to get to the bottom of this is so he does NOT kill his diode.. ;D
 
jayrob

jayrob

0
Joined
Sep 21, 2007
Messages
9,862
Points
113
Gazoo said:
I think I may have figured it out...we always overlook the obvious. You say it only puts out that much milliwatts when the head is attached to the body. The reason for this is because your diode/ flashlight head is not isolated from the body, so the regulator isn't doing anything! You are running the diode straight off the battery. I suspected something like this all along because that is just exactly how your diode has been behaving. Sorry it took me this long to figure it out.

@AMK....The reason I have been trying to get to the bottom of this is so he does NOT kill his diode.. ;D
Click to expand...

That makes perfect sense! I never thought of that because I have never used the AMC7135 drivers before. The DDL drivers are a direct connect from the negative side of the battery to the LD. But the 7135 is not! So, clipping the silicon diode was not an issue at all. The measurement was made with the heatsink separated from the MXDL housing.

Well, I guess these open can diodes are very sturdy to say the least huh? Thanks for everybody's help on this. Especially you Gazoo... and for saving my diode!
Jay

P.S. I guess that after I insulate the heatsink from the MXDL housing, I will be able to live with around 200mW! I have a feeling that at this power, the open can diode will out last the Sony...

Edit: Keep reading! After re-designing the MXDL, and going back to a custom DDL driver and a Meredith module using 2 x 3.6 batteries, this baby ends up putting out over 300mW after all! Follow the thread to see how...Also, check out a nice match light video on pg. 4!
Jay
 
Gazoo

Gazoo

0
Joined
Jun 9, 2007
Messages
3,206
Points
38
;D Well yeah, it does go to show how sturdy these diodes are electrically. I am surprised your regulators are not putting out at least 340ma's...maybe you have one that does. It would be nice if you could get closer to 250mw's out of that flashlight with a glass lens...but we really can't complain with 200mw's.

Anyway I have taken some advil...this gave me a headache and I ave gone completely bald..lol...j/k.

But I do thank you too Jay, this has been a very good experience for us and now we will know what to tell others if they have this problem. You truly do some amazing stuff making things..I think your ice box will always be the star of the show.. :)
 
jayrob

jayrob

0
Joined
Sep 21, 2007
Messages
9,862
Points
113
Gazoo said:
;D Well yeah, it does go to show how sturdy these diodes are electrically. I am surprised your regulators are not putting out at least 340ma's...maybe you have one that does. It would be nice if you could get closer to 250mw's out of that flashlight with a glass lens...but we really can't complain with 200mw's.

Anyway I have taken some advil...this gave me a headache and I ave gone completely bald..lol...j/k.  

But I do thank you too Jay, this has been a very good experience for us and now we will know what to tell others if they have this problem. You truly do some amazing stuff making things..I think your ice box will always be the star of the show.. :)
Click to expand...

Wow those are some nice compliments! Thank you. Of course, I haven't done anything by myself... A lot of the ideas that went into my Ice Box, I got from you! (yes it is my favorite) So much great advice and help here! I think I may put the open can loaded heatsink back into a different MXDL and run it with 2 - 3.6 RCR123s and a DDL driver to try to get around 250mW in this aluminum heatsink. I will save the drilled out MXDL and use a 7135/1050mA driver for a Cree Q5 emitter. It will be much easier to isolate the emitter, than to isolate this heatsink. Once again, I am very happy that you have figured this out and helped me save this diode!
Thanks again,
Jay
 
Gazoo

Gazoo

0
Joined
Jun 9, 2007
Messages
3,206
Points
38
Jay I am always happy to help out. This was a humdinger though... ;D You will do fine with the 317 in that body with 2 RCR123's. In fact I would set it at 400ma's and keep your duty cycles reasonable.
 
You must log in or register to reply here.




Top